X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=ccan%2Ftal%2Ftal.c;h=0e3c97b390003dfbae3ad82687ce3f35c5d52ce0;hb=41a0af50bf7e9cee7ad5ffdd288647ea2c3a6c38;hp=2a2eca77c04f5bbd37cc35e4ee4c4507e17ec33a;hpb=58277ab6c8b4dd6bb66638b88bd8505f46fdcb07;p=ccan

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index 2a2eca77..0e3c97b3 100644
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -2,13 +2,13 @@
 #include <ccan/tal/tal.h>
 #include <ccan/compiler/compiler.h>
 #include <ccan/list/list.h>
-#include <ccan/take/take.h>
 #include <ccan/alignof/alignof.h>
 #include <assert.h>
 #include <stdio.h>
 #include <stddef.h>
 #include <string.h>
 #include <limits.h>
+#include <stdint.h>
 #include <errno.h>
 
 //#define TAL_DEBUG 1
@@ -16,6 +16,9 @@
 #define NOTIFY_IS_DESTRUCTOR 512
 #define NOTIFY_EXTRA_ARG 1024
 
+/* This makes our parent_child ptr stand out for to_tal_hdr checks */
+#define TAL_PTR_OBFUSTICATOR ((intptr_t)0x1984200820142016ULL)
+
 /* 32-bit type field, first byte 0 in either endianness. */
 enum prop_type {
 	CHILDREN = 0x00c1d500,
@@ -27,7 +30,8 @@ enum prop_type {
 struct tal_hdr {
 	struct list_node list;
 	struct prop_hdr *prop;
-	struct children *parent_child;
+	/* XOR with TAL_PTR_OBFUSTICATOR */
+	intptr_t parent_child;
 };
 
 struct prop_hdr {
@@ -73,7 +77,7 @@ static struct {
 	struct tal_hdr hdr;
 	struct children c;
 } null_parent = { { { &null_parent.hdr.list, &null_parent.hdr.list },
-		    &null_parent.c.hdr, NULL },
+		    &null_parent.c.hdr, TAL_PTR_OBFUSTICATOR },
 		  { { CHILDREN, NULL },
 		    &null_parent.hdr,
 		    { { &null_parent.c.children.n,
@@ -94,19 +98,19 @@ static inline void COLD call_error(const char *msg)
 	errorfn(msg);
 }
 
-static bool get_destroying_bit(struct children *parent_child)
+static bool get_destroying_bit(intptr_t parent_child)
 {
-	return (size_t)parent_child & 1;
+	return parent_child & 1;
 }
 
-static void set_destroying_bit(struct children **parent_child)
+static void set_destroying_bit(intptr_t *parent_child)
 {
-	*parent_child = (void *)((size_t)*parent_child | 1);
+	*parent_child |= 1;
 }
 
-static struct children *ignore_destroying_bit(struct children *parent_child)
+static struct children *ignore_destroying_bit(intptr_t parent_child)
 {
-	return (void *)((size_t)parent_child & ~(size_t)1);
+	return (void *)((parent_child ^ TAL_PTR_OBFUSTICATOR) & ~(intptr_t)1);
 }
 
 /* This means valgrind can see leaks. */
@@ -378,7 +382,7 @@ static bool add_child(struct tal_hdr *parent, struct tal_hdr *child)
 			return false;
 	}
 	list_add(&children->children, &child->list);
-	child->parent_child = children;
+	child->parent_child = (intptr_t)children ^ TAL_PTR_OBFUSTICATOR;
 	return true;
 }
 
@@ -498,6 +502,8 @@ void *tal_free(const tal_t *ctx)
 		struct tal_hdr *t;
 		int saved_errno = errno;
 		t = debug_tal(to_tal_hdr(ctx));
+		if (unlikely(get_destroying_bit(t->parent_child)))
+			return NULL;
 		if (notifiers)
 			notify(ignore_destroying_bit(t->parent_child)->parent,
 			       TAL_NOTIFY_DEL_CHILD, ctx, saved_errno);
@@ -654,6 +660,9 @@ size_t tal_len(const tal_t *ptr)
 {
 	struct length *l;
 
+	if (!ptr)
+		return 0;
+
 	l = find_property(debug_tal(to_tal_hdr(ptr)), LENGTH);
 	if (!l)
 		return 0;